Feedback PSDImporter generated sprite atlas is less optimal than regular Unity sprite atlas?

I noticed that the PSDImporter generates a sort of sprite atlas texture nested as a sub-asset. In my case, this is a texture 4096 x 4096 px. Most of the space on this atlas is wasted with transparency, however.

After the build this file is 21.3 mb large:



When I manually create a regular Unity sprite atlas asset and add in the sprites from the PSD file layers, the generated texture is 4096 x 2048 px, which is wasting a lot less space (only 8 mb large):



So is there any reason for the PSDImporter to generate the internal atlas square? If not, would it be possible to update the behaviour so that it also uses ratios such as 4096 x 2048?